The present invention relates to vehicle suspension systems and methods and, more specifically, to suspension systems and methods configured to be used as with bicycles.
A bicycle typically comprises a frame assembly, wheels, a seat, a fork, a handle bar, a pedal set, and a brake system. The fork is rotatably attached to the frame assembly, and a seat post of the seat is rigidly attached to the frame. A hub of the front wheel is attached to the fork, and a hub of the rear wheel is attached to the frame assembly. The pedal set is supported by the frame and connected to the rear wheel. A rider of the bike sits on the seat, grasps the handle bar with the hands, and rotates the pedals with the feet.
Conventionally, the fork and frame assembly acted as rigid structures with respect to the seat and handle bar, and shocks were transmitted to the handle bar through the front wheel and the fork and to the seat through the rear wheel, the frame assembly, and the seat. These shocks were in turn transmitted to the rider, primarily through the handle bar and the seat.
To reduce shocks on the rider, various suspension systems have been employed. Initially, the bicycle seat was padded, and springs were arranged between the seat and the frame to inhibit transmission of shocks to the rider sitting on the seat. Springs have also been arranged in the seat posts to inhibit transmission of shocks to the rider. Suspension seats and seat posts may be applied to a conventional bicycle having a rigid frame and fork but provide only limited shock absorption.
Another class of bicycle suspension systems requires the modification of one or both of the frame and fork.
One form of vehicle suspension system that requires a modified frame entirely eliminates the part of the frame that receives the seat post. The seat is instead supported on a spring arm extending backwards from the modified frame to inhibit transmission of shocks to the rider sitting on the seat. This variety of vehicle suspension system requires a radically modified frame and may not be applied to most bicycle frames on the market.
Suspension systems have been applied to the fork to inhibit transmission of shocks to the rider's arms. In particular, the fork is divided into a steerer member and a fork member. The steerer member is connected to the handle bar, and the steerer member is connected to the fork member by a pneumatic suspension system arranged to resiliently oppose movement of the fork member to move relative to the steerer member along a fork axis. Suspension forks, while highly effective for off-road riding, are relatively heavy and expensive and are not preferred for use on bicycles built for road biking.
Full suspension bicycles typically employ, in addition to a shock absorbing fork, a two piece frame assembly in which a first part of the frame is pivotably connected to a second part of the frame. The first part of the frame typically supports the seat and the pedal set, and the second part of the frame supports the rear wheel. In this case, a spring and/or pneumatic shock absorbing system is arranged to resist movement of the second part of the frame relative to the first part of the frame. Again, full suspension bicycles, while highly effective for off-road riding, are relatively heavy and expensive and are not preferred for road biking.
The need exists for vehicle suspension systems and methods that effectively reduce shocks on the rider.